Conversion top for fuel control valves



Feb. 7, 1956 R. w. JOHNSON ET AL 2,733,955

CONVERSION TOP FOR FUEL CONTROL VALVES Filed Oct. 20. 1950 Te. ERATURE. R PON$IV5 CHARGE.

9 Z Y M 4 2 Z 4 u ,6 r oo l L F MU ma 2m \[23 4 Z 1o 5 M4 4 86 f; 5 5 8 4 m m m m ROY W. Jou-msou BY FERDINAND F. Hmsaa A-r-roanuw United States Patent 2,733,955 CONVERSION TOP FOR FUEL CONTROL VALVES Roy W. Johnson and Ferdinand F. Heiser, Milwaukee,

Wis., assignors to AP Controls Corporation, a corporation of Wisconsin Application October 20, 1950, Serial No. 191,282

3 Claims. (Cl. 2978) This invention relates to a device for converting manually operated fuel flow controls to automatic operation. Devices of this type are referred to as conversion tops and may be regulated in response to electric thermostat demand or may beresponsive to ambient temperature. The present conversion top is of the latter variety and represents an improvement over prior devices.

An object of the'present invention is to provide a simple, compact, readily adjustable conversion top which responds to ambient temperature.

Another object is to provide an ambient temperature responsive conversion top which is reliable and accurate.

A further object is to provide an ambient temperature responsive conversion top of simplified construction permitting of lower manufacturing cost.

Other objects and advantages will be pointed out in,

or be apparent from, the specification and claims, as will obvious modifications of the single embodiment shown in the drawings, in which:

Fig. 1 is a fragmentary view, partly in section, of theconversion top mounted on an oil control valve;

Fig. 2 is a top view of the conversion top;

Fig. 3 is a bottomview; and

Fig. 4 is a fragmentary top view. with the annular indicia-bearing collar removed.

Referring to the drawings in detail, the present conversion top 10 is adapted to be mounted on manually operated oil control valves of the type employed to meter liquid fuel flow to a spaceheater. The oil control valve may be 'of the type illustrated in the drawings wherein the mechanism is contained within a casing 12 which houses a float controlled inlet valve, not shown, and an outlet valve which may be regulated by means of manually operated knob 14. The knob 14 may be of the type shown in Patent No. 2,317,063 (which also shows an electric conversion top) wherein rotation of the knob actuates lever 16 pivoted at 18 to regulate the outlet valve through valve stem 20. The outlet valve is biased open by spring 21. In the illustrated control a leaf spring 22 is employed to transmit the force from the lever 16 to the valve stem 20. The oil control valve is provided with a push pin 24 projecting through the top of the casing 12 and resting on lever 26 to move the levers 26 and 16 downwardly when the pin is pushed down. This movement will cause the outlet valve to be closed. The outlet valve may be regulated by push pin 24 between the closed position and the open position as limited by the setting of the manual control knob 14. Thus if knob 14 is set to allow the outlet valve to open to its maximum, pin 24 may be actuated to regulate flow between the full open and closed positions. When the knob is set to allow only partial flow, pin 24 may be employed to regulate the flow between such partial flow as the upper limit and the closed position.

The conversion top is adapted to be mounted on the oil control valve to regulate flow from the outlet by actice ing on pin 24. The top includes a stamped housing 28 adapted to be secured to the control valve by screws 29, 29 and provided with a fulcrum 30 riveted to the underside of the housing at 32, 32. Notch 36 on lever 34 rests on the fulcrum with the lever projecting through housing aperture 38 to overlie push pin 24. Finger 40 projects from the housing 28 to prevent accidental actuation of the lever from above. Rivet 42 secures name plate 44 to the top side of housing 28 and secures depending post 46 to the underside of housing 28. Post 46 projects downwardly through aperture 48 in lever 34 and is provided with head 50 which serves to mount cupped seat 52 for spring 54 compressed between the seat and lever 34 to bias lever 34 upwardly in the valve closing direction.

An internally apertured, externally threaded nipple 56 is mounted in the top portion of housing 28. Threaded member 58 is mounted on nipple 56 and carries charged bulb 6% which includes a flexible bellows 62 hermetically sealed to the bulb by means of ring 64 and suitable solder 66. The lower end of the bulb is flanged and held between gaskets 68, 70 by staking the upper edge 72 of member 58. The bulb contains a temperature responsive liquid charge which flexes bellows 62 as the temperature varies.

Movement of bellows 62 is transmitted to lever 34 by means of pin 74 which acts between the bellows pressure pad 76 and depression 78 in lever 34. Pin 74 is of the overtravel type wherein head 80 and the shank of the pin may move downwardly into hollow head 82 against the compression of spring 84 if the temperature should increase to the point where further movement of lever 34 is impossible and further bellows movement must be allowed to prevent damage to the bellows. It will be understood, of course, that in normal operation the pin parts are extended and the pin acts as a solid unit. The small spring 86 wrapped on the shaft of pin 74 spaces spring 84 and prevents interference with the walls of bellows 62. V

Member 58 may be rotated on nipple 56 to vary the height of bellows 62 above lever 34 and thus regulate the response temperature of the bulb 60. Cupped valve seat 88 receives the upper end of compressed spring 9% and is notched at 92 to receive a housing lug 94 to prevent rotation of the cup as member 58 is turned. The spring and cup arrangement serves to hold the member 58 and bulb 60 in their adjusted position and prevents stressing the spring abnormally. Housing lug 94 also functions to limit rotational movement of member 58 by coacting with land 96 on the underside of collar 98 fixed on member 58 by means of set screw 100 after the conversion top has been adjusted. The collar is provided with indicia 102 which cooperate with pointer 183 to indicate the temperature selected within the range limited by contact of land 96 with lug 94 as the collar is rotated clockwise and counter-clockwise. Should it be necessary to remove the bulb or re-set the top, set screw 1% may be backed ofr to free member 58 for further movement.

The charged bulb 60 responds to ambient temperature to flex bellows 62 and actuate lever 34 through pin 74. As lever 34 moves up and down, push pin 24 on the oil control valve is raised or lowered to control the position of the spring biased outlet valve. When the ambient temperature rises above the selected temperature, the charge in bulb 60 increases to collaspe bellows 62 to move the valve operating lever 34 toward the valve closed position. As the ambient temperature falls, the bellows expands as the bulb pressure decreases and thevalve closes. This simple device is completely self-contained and provides for accurate response to ambient temperature to regulate flow from the oil control valve to the 3 burner to maintain the selected temperature in the space heated by the burner. In practice the control selects a position wherein the flow gives a burner output substantially equal to the requirement rather than operating on an on-olf cycle.

It will be noted that the present conversion top is readily adjustable and requires no external wiring or thermostats forsatisfactory operation in conjunction with space heaters. The structural simplicity. of the top lends itself to economical manufacture. The manner in which the lever spring 54 and bellows push pin '74- coact on lever 34 to hold the lever on fulcrum 3t avoids the need for pivot pins and makes rapid assembly possible. it will be appreciated that the principal use for such a conversion top is in conjunction with space heaters rather than in installations where the burner is remote from the space which is to be heated.

Although but one embodiment of the present invention has been illustrated and described, it will be apparout to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of he appended claims.

We claim: l

1. An automatic control for fuel control valves comprising a housing, a lever fulcrumed within said housing, thermally-responsive means for actuating the lever, means for adjustably mounting said thermally-responsive means in respect to said lever, said adjustable mounting means including a threaded member carried by the housing, a nipple threadedly engaged with said threaded member, and means for securing the thermally-responsive means to said nipple, said thermally-responsive means includ ing a bulb member, and a bellows within said bulb member and defining therewith an expansible chamber, temperature-responsive material within said chamber and a lever-actuating pin operatively connected to the bellows and operatively engaging said lever, spring means operative upon the lever in opposition to said pin, said nipple being provided with an annular shoulder, and friction means for holding the nipple in adjusted position including an inverted cup-shaped member surrounding the nipple, and a coil spring interposed between the housing and said cup-shaped member and pressing the latter into frictional engagement with the annular shoulder on said nipple, said inverted cup-shaped member and the housing being provided with cooperative stop means for holding the inverted cup-shaped member against rotation as the nipple is adjusted on said threaded member.

2. An automatic control for fuel control valves comprising a housing, a lever fulcrumed Within said housing, thermally-responsive means for actuating the lever, means for adjustably mounting said thermally-responsive means in respect to said lever, said adjustable mounting means including a threaded member carried by the housing, a nipple threadedly engaged with said threaded member, and means for securing the thermally-responsive means to said nipple, said thermally-responsive means including a bulb member, and a bellows within said bulb member and defining therewith an expansible chamber, tempera- 4 l ture-responsive material within said chamber and a leveractuating pin operatively connected to the bellows and operatively engaging said lever, a collar member adjustably supported on the upper end of said nipple through which the bulb extends and means for releasably securing the collar to the nipple in an adjusted position, said collar having a depending portionsurrounding the nipple, and stop means cooperatively carried by the collar and the housing for limiting rotation of the nipple on said threaded member, said collar and said housing being provided with cooperative indicia for indicating a desired ambient temperature corresponding to the position of adjustment of the nipple on said threaded member.

3. An automatic control for fuel control valves comprising a housing, a lever fulcrumed within said housing, thermally-responsive means for actuating the lever, means for adjustably mounting said thermally-responsive means in respect to said lever, said adjustable mounting means including a threaded member carried by the housing, a nipple threadedly engaged with said threaded member, and means for securing the thermally-responsive means to said nipple, said thermally-responsive means including a bulb member, and a bellows within said bulb member and defining therewith an expansible chamber, temperature responsive material within said chamber and a leveractuating pin operatively .connected to the bellows and operatively engaging said lever, spring means operative upon the lever in opposition to said pin, said nipple being provided with an .annular shoulder, and friction means for holding the nipple in adjusted position including an inverted cup-shaped member surrounding the nipple, and a coil spring interposed between the housing and said cup-shaped member and pressing the latter into frictional engagement with the annular shoulder on said nipple, said inverted cup-shaped member being provided with stop means, a collar adjustably-supported on the upper end of said nipple and through which the bulb extends, and means for releasably securing the collar to the nipple in an adjusted position, said collar being provided with a depending skirt portion, said threaded member, said nipple, said inverted cup-shaped member, said spring, and said skirt portion being concentrically nested about the axis of rotation of the nipple with the skirt portion of the collar outermosusaid skirt carrying stop means to limit the rotation .of the nipple on the threaded member, and stop means on the housing cooperating with the stop means on the inverted cup-shaped member and on the skirt of the collar.

References Cited in the file of this patent UNITED STATES PATENTS 1,733,888 Landgraf Oct. 29, 1929 1,794,610 Halsey Mar. 3, 1931 1,850,727 Robertshaw Mar. 22, 1932 1,961,325 Anderson June 5, 1934 2,239,525 Johnson et a1. Apr. 22, 1941 2,253,866 Quoos Aug. 26, 1941 2,317,063 Johnson Apr. 20, 1943 2,387,793 Holmes Oct. 30, 1945 2,527,622 Dibert Oct. 31, 1950 

